Merriam-Webster Logo
SINCE 1828
Menu
×

An Encyclopædia Britannica Company

See What's Trending Now See More Trending Words

SOS

play
noun \ ˌes-(ˌ)ō-ˈes \

Definition of SOS

1 :an internationally recognized signal of distress in radio code ‧ ‧ ‧ - - - ‧ ‧ ‧ used especially by ships calling for help
2 :a call or request for help or rescue

See SOS defined for English-language learners

See SOS defined for kids

From the M-W Editors

sos
7 Good Stories That Just Aren't True
alt-59c448f88ea38
Trending: Kim Jong Un: Trump a 'Dotard'
alt-59c94ad823f29
'Meat Sweats': The Cookout's Worst Nightmare
video-title-words-of-the-year-1066
Words of the Year: 1066

First Known Use of sos

1910

SOS Defined for English Language Learners

SOS

play
noun

Definition of SOS for English Language Learners

  • : a signal used by ships and airplanes to call for help

SOS Defined for Kids

SOS

play
noun \ ˌes-ō-ˈes \

Definition of SOS for Students

1 :an international radio code distress signal used especially by ships and airplanes calling for help
2 :a call for help

Medical Dictionary

SOS

abbreviation

medical Definition of SOS

if occasion require; if necessary —used in writing prescriptions

Origin and Etymology of sos

Latin si opus sit

Learn More about sos

  1. See words that rhyme with SOS Spanish Central: Translation of SOS Nglish: Translation of SOS for Spanish speakers Britannica.com: Encyclopedia article about SOS

Seen and Heard

What made you want to look up SOS? Please tell us where you read or heard it (including the quote, if possible).

show hide

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

WORD OF THE DAY

broadside

play

a strongly worded attack

Get Word of the Day daily email!

TRENDING NOW

  1. dotage, dotard a state or period of senile decay

  2. otherwise "in other respects"

  3. federalism Graham says bill gives power to states

  4. bodega "Don’t mess with the beloved bodega."

  5. carceral Of, relating to, or suggesting a jail or prison

SEE ALL

BROWSE DICTIONARY

SOS

Test Your Vocabulary

Merriam-Webster's New Words Quiz—Fall 2017 Edition!

  • young-plant-shoots
  • Which of the following is a new sense of the word bunny?
True or False

Test your knowledge - and maybe learn something along the way.

TAKE THE QUIZ
Word Winder's CrossWinder

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Words at Play

image961678022
10 Uncommon Words for 'Drunkard'

Tosspots, stewbums, and all the rest

alt-59c94ad823f29
'Meat Sweats': The Cookout's Worst Nightmare

They're real, but is meat the cause?

alt-59c919f342079
'Diffuse' vs. 'Defuse'

Let us defuse the situation.

alt-59c52d6ee2f72
Breathing Life Into 'Inspire'

The word's origins are quite literal

Ask the Editors

video-title-words-of-the-year-1066
Words of the Year: 1066

Or, Why Pig Meat is Called 'Pork' and Cow Meat is Called 'Beef'

payday
How Often Is 'Biweekly'?

Don't get us started on 'bimonthly'

video-irregardless-grammar-peeve-blend-of-the-synonyms-irrespective-and-regardless
Irregardless

It is in fact a real word (but that doesn't mean you should use it).

video-moose-goose-weird-plurals
Weird Plurals

One goose, two geese. One moose, two... moose. What's up with that?

Word Games

young-plant-shoots
Merriam-Webster's New Words Quiz—Fall 2017 Edition!

You're going to have to memorize the dictionary again.

Take the quiz
stylized-drawing-of-woman-pole-vaulting-across-gap-to-get-trophy
Challenging Vocabulary Quiz Returns!

No tricks, just difficult words.

Take the quiz
True or False
True or False?

Test your knowledge - and maybe learn something along the way.

Take the quiz
Word Winder's CrossWinder
Word Winder's CrossWinder

A game of winding words.

Play the game